Gaffer Drone

August 8, 2014

I'm one of the few people who actually reads the credits at the end of a movie or television show. Actually, I should write that I try to read the credits, since they usually scroll or flash very fast. In the industry, scrolling credits are called "the crawl." It's there that you find such colorful characters as "best boy" and "gaffer."

A gaffer is the chief electrician on a film or television crew. As such, he's responsible for the lighting. A best boy is his assistant, and his role is to manage the lighting crew. The etymology for "best boy" comes from the expression for a master's most experienced apprentice.

Proper lighting is essential to still photography as well as film making. It's easy to distinguish by the lighting whether a particular photograph on the Internet was shot by a professional, rather than an amateur. In my own photography, one thing that I check when posing people outdoors is patchy lighting. People posed under trees can have patches of light on their faces that ruin an otherwise good photo.

"If somebody is facing you, the rim you would see is on the edge of the shoulder, but if the subject turns sideways, so that he's looking 90 degrees away from you, then he's exposing his chest to the light, which means that you'll see a much thicker rim light... So in order to compensate for the change in the body, the light has to change its position quite dramatically."[2]

The drone computes its required position twenty times each second. The researchers tried a complex algorithm which analyzed the silhouette of the subject, but that proved to be too slow. Instead, it looks at most dramatic change in light intensity in the image, and it measures its width. The drone uses LIDAR for rangefinding.[2]

Although the experiments were facilitated by their being done in a laboratory equipped with cameras that allowed a determination of the drone position for use in the algorithm, there's no reason why accurate enough position sensors couldn't be incorporated into the drone, itself.[2]

The drone positioning algorithm for the rim lighting experiment used simple geometry.

These experiments were done indoors, but there's been a lot of interesting drone photography done outdoors. Realtors have used drones to obtain aerial footage of their listed properties, which is a public example of how useful drones can be. The US Federal Aviation Administration (FAA), in a controversial ruling, has told realtors that they must stop this practice.[4]